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Oracle分区表的层次查询如何才能用到分区?(三)
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1 - access("T"."PARENT_ID"=PRIOR "T"."ID" AND PRIOR "T"."CODE"='0306')
filter("T"."ID"=12)
统计信息
----------------------------------------------------------
1 recursive calls
0 db block gets
55 consistent gets
0 physical reads
0 redo size
557 bytes sent via SQL*Net to client
360 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
2 sorts (memory)
0 sorts (disk)
2 rows processed
只有这一种写法才能用到分区
SQL> select * from test t
start with (t.id = 12
and t.code = '0306')
connect by prior t.id = t.parent_id
and t.code = '0306';
执行计划
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Plan hash value: 3571852076
--------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
--------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 2 | 84 | 9 (34)| 00:00:01 | | |
|* 1 | CONNECT BY WITH FILTERING | | | | | | | |
|* 2 | TABLE ACCESS BY GLOBAL INDEX ROWID| TEST | 1 | 15 | 1 (0)| 00:00:01 | 6 | 6 |
|* 3 | INDEX UNIQUE SCAN | SYS_C0010758 | 1 | | 0 (0)| 00:00:01 | | |
|* 4 | HASH JOIN | | 1 | 28 | 6 (17)| 00:00:01 | | |
| 5 | CONNECT BY PUMP | | | | | | | |
| 6 | PARTITION LIST SINGLE | | 2 | 30 | 4 (0)| 00:00:01 | KEY | KEY |
| 7 | TABLE ACCESS FULL | TEST | 2 | 30 | 4 (0)| 00:00:01 | 6 | 6 |
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Predicate Information (identified by operation id):
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1 - access("T"."PARENT_ID"=PRIOR "T"."ID")
filter("T"."CODE"='0306')
2 - filter("T"."CODE"='0306')
3 - access("T"."ID"=12)
4 - access("connect$_by$_pump$_002"."prior t.id "="T"."PARENT_ID")
统计信息
----------------------------------------------------------
0 recursive calls
0 db block gets
16 consistent gets
0 physical reads
0 redo size
557 bytes sent via SQL*Net to client
360 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
4 sorts (memory)
0 sorts (disk)
2 rows processed